Fan or blower



l Oct. 6, 1936. B. M. GUTHRIE FAN OR BLOWER Filed June 6, 1955 INVENTOR. BER/men MORSE GUrHR/E BYy ATTORNEY,

Patented Oct. 6, 1936 UNITED STATES PATENT FFICE FAN OR BLOWER lration of Illinois Application June 6,

2 Claims.

This invention relates to improvements in fans vor blowers, and more particularly to improvements in the construction and operation of blower assemblies of centrifugal type.

An object of the present invention is attained in the `provision of an improved blower structure which `is designed to dampen or minimize to a substantial degree, the objectionable noise attendant upon the operation of the blower. A minimization of the noise of operation is particularly desirable where the 4blower is utilized in 'conjunuction with domestic stoker assemblies, or when the blower is to be used indomestic ventilation systems and the like.

.A further object is attained in the provision of' an improved blower assembly including a blower air regulating `damper and a device for absorbing and damping to a substantial degree, the noise resulting from the inflow of air to the blower. The blower damper provided in the presently preferred embodiment of the invention, as illustrated in the accompanying drawing, is arranged to-be readily adjustable'through a control element accessible exteriorly of the blower housing.

A `still'further'object is attained in the provivsion of'an improved blower .assembly of the type described, which includes,'in addition to the foregoing features, a safety feature in the form of a Vguard structure for the protection of the blower against objects coming into contact with the fan, whereby to prevent possible damage to or breakage of the fan blades. The'guard structurealso serves to prevent injury to the person, which Votherwise might occur from contact with the moving fan blades.

Further objects and advantages will appear from .the vfollowing description, and 'from the drawing,'in which:

Fig. 1 is an assembly elevation of -a blower structure embodying the improvements of the present invention; Fig. 2 is .an end elevation of the .structure as viewed from line 2-2 lin Fig. l, a portion thereof being shownin sectionand the blower casing proper being broken away to show the air inlet opening to the blower fan, and Fig. 3 is a transverse sectional elevation of the structure, as viewed from line 3 3 in Fig. 2, with a portion thereof broken away to illustrate certain features of the invention.

Referring now to the drawing by suitable characters of reference, I illustrates a blower casing which may be of conventional form for a blower of centrifugal type, the casing having the usual peripheral blower discharge neck I2 which is adapted for connection to a conduit (not shown) 1935, Serial No. 25,237

for the delivery of air to a device or apparatus requiring a forced air supply. The blower fan, of which only the blade Ifl and a portion of the fan hub I6 are shown, is securedto the shaft i8 which is journalled in a bearing carried by the casing iB. The shaft i8 may be driven by any suitable prime mover (not shown), such as an electric motor. Delivery of air to the blower fan is made thro-ugh an inlet port or opening 22 `in a side wall 23 of the casing i6, the air inlet in a blower of the present type, being yformed and arranged in the wall 23 so that air will be admitted to the axial portion of the blower fan.

The particularly novel features of the present invention are to be found in thestructure of an open-side, cylindrical housing 24 and in the relation of the housing to the blower casing IG. The housing is comprised of a cylindrical wall 26 and an end wall'28, and may be formed of sheet metal or other suitable material, as desired. The dimensions of the housing are such as to permit the reception of the blower casing therein, in the manner illustrated in Figs. l and 2, so that a substantial clearance space, such as 3i), obtains between the wall and the peripheral surface of the casing ill, and also provides a substantial clearance or space 32 between the housingwall 28 and the sidewall 23 of the casing. The housing 26 and-casing iB are secured together in the described spaced relation, preferably by spacing members 34 which may be secured to the casing and housing in any suitable manner permitting of ready removal, whereby to provide for .a separation of the parts for repair or replacement purposes. The housing is further provided with a slot 35 in a portion of the wall 25 for the reception of the casing discharge neck l2 in the assembly of the housing 24 to the casing.

Extending through a central portion of the casing wall 28 is a screw 3E which threadedly engages a nut 38 iixedly secured to the wall 28, inwardly of the housing. For convenience in manufacture, the nut 33 may be welded to the wall 28, as shown at 39 in Fig. 2. The screw 35 carries on its inner end, a damper disc 40 which may be .secured thereto in any suitable manner, as by welding at 4l (Fig. 2). The damper 40 is arranged opposite the blower inlet port 22, to oppose or restrict the air flow thereto in any desired degree, as determined by the relative spacing of the damper and the inlet opening. The end of the screw 36 externally of the housing, is provided with a knob or handle 42 for ready manual adjustment of the damper to effect any desired degree of air control in the admission of air to the blower.

In the operation of the improved blower described above, air is delivered to the space or chamber 32 in the housing 24 through the substantially annular space or channel 3&3, whence it flows between the damper i0 and the wall 23 of the blower casing I0, and through the blower inlet port 22 to the axial portion of the blower fan. The air is then peripherally discharged by the revolving fan blades, through the discharge duct I2, whence it is directed to a place of utilization. The volume of airflow through the inlet port 22 is, of course, directly controlled by the damper element 4I] which may be regulated at will simply by actuating the screw S, by means of the handle 42. It will be observed that the air flow entering the housing 261 through the channel 30, is first directed against the housing Wall 28 and is re-directed thereby, in a reverse direction, toward the blower casing and the casing inlet port 22. Thus the structural arrangement of the blower assembly effects an indirect or circuitous path for the airflow to the blo-wer inlet port. The inrush of air impinging on the housing wall 28, might, if this element were of light construction, create objectionable sound vibrations which, but for present provisions, could be transmitted to al1 parts of the blower structure, thereby creating, in many instances, a considerable noise nuisance. This form of nuisance may become particularly objectionable where the blower is utilized in domestic Stoker assemblies. Hence, the present invention provides in the structure of the housing 24, a device for absorbing noise-producing vibrations resulting from the inrush of air into the chamber 32 and its impingement against the housing wall 28.

The vibration absorbing and sound dampening device comprises, in the example shown, an element 411 suitably arranged within the housing 24 in the path of air flow to the blower inlet 22, the dampening element being formed of a suitable grade of felt or other similar material having good sound absorbing and dampening characteristics. The element 4d substantially covers the inner surface of the housing wall 28, as shown in Figs. 2 and 3, and its central portion is cut away as at 45, to clear the nut 38. The element may be secured to the wall 28 in any suitable manner, such as by an adhesive material (not shown) between the engaging surfaces of the element and Wall. 'Ihe dampening action of the element M is readily apparent from an inspection of Fig.v 2, where it will be observed that air entering the chamber 32, as shown by the arrows, with the considerable velocity created by the revolving fan, impinges upon the felt element 413, and any tendency for such air ow to cause vibrations to be set up in the wall 28 as well as in the damper element 4D, will be minimized by the resilience and dampening effect of the element 44. The absorbent element 44 being directly connected to the wall 28, will tend to kill any vibrations of the metal or other material of the wall, and its proximity to the damper lill will tend markedly to obviate markedly any sympathetic vibrations of the latter element.

It Will be readily appreciated that the housing 24 provides an effective protection for the fan blades, against the introduction of foreign objects thereto which otherwise might result in damage to or actual breakage of the fan blades. The housing further safeguards against po-ssible contact with the revolving fan blades, on the part of persons or animals in the vicinity of the blower mechanism.

It is to be understood that the present description relates only to a single preferred embodiment of this invention, and that alterations and modifications may be made therein without departing from the spirit or full intended scope of the invention, as dened by the appended claims.

I claim:

l. In combination with a blower of centrifugal type, a blower casing having air inlet and discharge openings, a housing substantially enclosing said casing, the housing being of substantially greater diameter and depth than the blower casing, the peripheral walls and a pair of the corresponding side walls of said housing and casing being spaced to dene a substantially annular passage for the flow of air into the housing, and a chamber adjacent the casing inlet, a damper element of disc form adjustably carried by the housing and overlying said casing inlet in said chamber, a threaded control member operable exteriorly of the housing for effecting adjustments of said damper, and a resilient disc element carried by the housing in said chamber and across the path of initial air flow into the housing, and adapted to effect a dampening of the sound vibrations created by the flow of air to the casing inlet.

2. In combination with a blower of centrifugal type, a blower casing having an air inlet port, a housing substantially conforming in shape to said casing, and disposed in enclosing relation thereto, so that the dimensions of the assembly do not substantially exceed those of the housing, the walls of said housing and casing being radially spaced to dene a substantially annular air inlet passage, and spaced depthwise or axially so that their corresponding sidewalls define a chamber for the flow of air to said inlet port, a damper disc in said chamber, overlying said inlet port, a threaded adjusting element extending through a wall portion of said casing and supporting said damper, said element being accessible exteriorly of the housing, and a disc element formed of a fibrous material, carried internally of the housing at one side of said chamber and so disposed in baffling relation to the path of air flow to said inlet port, said element being provided for absorbing and dampening sound vibrations created by the flow of air to said port.

BERNARD MORSE GUTHRIE. 

